Gas prices rose an additional 13 cents in the past week, making Dallas’ average of $3.59 per gallon the highest in the state.

And experts say prices will continue to rise this spring when refineries make their annual switch to the costlier “summer blend.”

“This is a little unusual, especially at this time of year when gas prices typically fall,” said Bernard Weinstein, associate director of SMU’s Maguire Energy Institute.

Weinstein laid the blame on the increasing cost of oil, which has gone up 20 percent in recent weeks.

Sharon Greer was filling up Monday morning at Fuel City in downtown Dallas, where gas was just under the Dallas average. Greer said gas prices are taking a toll on her budget.

“Something needs to be done,” she said. “One night you fall asleep, and the next morning the gas is up 10 more cents. It’s absolutely ridiculous.”

Renee Maughan, who commutes to Dallas daily, said his weekly bill has approached triple-digit territory.

“It’s horrible, especially when you have to drive to Dallas for work,” he said. “I spend almost $100 on gas every week.”

Earlier this month, the Energy Department reported that U.S. households spent an average of $2,912 on gasoline last year. That’s almost 4 percent of their pretax income, the highest percentage in 30 years.

Doug Shupe, senior public affairs specialist for AAA, said Dallas residents bear the brunt of the rise statewide because the city is a major center of commerce. On the bright side, he noted, several large refineries are expanding or undergoing maintenance now, which should make more gasoline available in the future.

“Once this maintenance ends, the rise of prices will slow down,” Shupe said.

“The steady climb of retail gas prices is likely to continue following double-digit increases in wholesale prices with fuel production tightening in the majority of the country’s refineries,” Laskoski said.

Still, local prices are well below the national average of $3.73 per gallon, which is 43 cents higher than a month ago. Texas’ average stands at $3.56 per gallon.